Overview
Symantec resolved a Denial of Service (DoS) and potential compromise vulnerability reported by ISS X-Force. The vulnerability was identified in the Entrust module responsible for handling ISAKMP negotiations that is used in some Symantec gateway products. Under certain conditions, the VPN component terminates abruptly impacting the availability of dynamic VPN services. A specifically crafted attack could potentially lead to further compromise of the VPN server.

Details
ISS X-Force notified Symantec of a vulnerability they discovered in the Entrust module running on some of Symantec's gateway products. The module, which implements the IKE key exchange protocol, was not properly validating incoming ISAKMP packets.

ISAKMP is a standard protocol used to negotiate dynamic VPN tunnels. By sending sufficiently malformed ISAKMP packets, an attacker could cause a DoS condition in the affected VPN component. Or, if specifically crafted, the malformed ISAKMP packets could potentially lead to further possible compromise of the VPN server.

Symantec Response
Symantec confirmed the vulnerable module and coordinated extensively with Entrust to finalize and thoroughly test a fix for the Entrust module impacting Symantec's affected products.
Symantec has released a hotfix to address this issue for affected Symantec gateway products. Symantec strongly recommends customers apply the appropriate hotfix for their affected product models/versions immediately to protect against this type of threat.
Product specific hotfixes are available via the Symantec Enterprise Support site http://www.symantec.com/techsupp.

Symantec is not aware of any active attempts against or organizations impacted by this issue.

CVE
The Common Vulnerabilities and Exposures (CVE) initiative has assigned Candidate CAN-2004-0369 to the ISS X-Force reported issue.
This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems.

Credit:
Symantec appreciates the actions of the X-Force research team in identifying this issue to Symantec and their cooperation and coordination while Symantec worked with Entrust to resolve all issues.

Symantec takes the security and proper functionality of our products very seriously. As founding members of the Organization for Internet Safety (OISafety), Symantec supports and follows the principles of responsible disclosure. Symantec also subscribes to the vulnerability disclosure guidelines outlined by the National Infrastructure Advisory Council (NIAC).

Please contact secure@symantec.com if you feel you have discovered a security issue in a Symantec product. A Symantec Product Security team member will contact you regarding your submission. Symantec strongly recommends using encrypted email for reporting vulnerability information to secure@symantec.com. The Symantec Product Security PGP key can be found at the end of this message.

Symantec has developed a Product Vulnerability Response document outlining the process we follow in addressing suspected vulnerabilities in our products. This document is available below.

Copyright (c) 2009 by Symantec Corp.
Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Security Response. Reprinting the whole or part of this alert in any medium other than electronically requires permission from secure@symantec.com.

Disclaimer
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